From:
Richard Palluzi <000006c59248530b-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject:
Re: [DCHAS-L] Curious about Teflon tape
Date:
Sep 21, 2023 10:40 UTC
Reply-To:
ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
Message-ID:
<006401d9ec77$fde95150$f9bbf3f0$@verizon.net>
In-Reply-To:
<CAJug0Owgrij=pjNdNiG4MMKjHWxYRGUnHAmew_a_ef1_AGtS6g**At_Symbol_Here**mail.gmail.com>
I believe you are talking about the CGA fitting which has a straight thread. This type fitting does not require Teflon tape and using it can damage the fitting. They should go on and off with a standard 10-12” wrench with only moderate force.
Teflon tape is sold as “approved” for certain services to meet fire code requirements. Typically it is a different color although, to the best of my knowledge, the composition is the same. (The color shows it can be traced back to an “approved” for the use sample at the testing laboratory.)
Feel free to call if I can help.
Richard Palluzi
BE(ChE), ME(ChE), PE, CSP,FAIChE
Pilot plant and laboratory consulting, safety, design, reviews, and training
www.linkedin.com/in/richardppalluzillc/
www.pilotplants.us
Richard P Palluzi LLC
72 Summit Drive
Basking Ridge, NJ 07920
rpalluzi**At_Symbol_Here**verizon.net
908-285-3782
From: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU> On Behalf Of Benjamin Ruekberg
Sent: Wednesday, September 20, 2023 3:57 PM
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Subject: [DCHAS-L] Curious about Teflon tape
Hello,
This is nothing to get excited about, just a matter of curiosity.
At our annual safety training we were told not to use Teflon tape when attaching regulators to gas cylinders. The ultimate reason given was that the tape would not allow the regulator's ball to fit tightly to the gas cylinder's socket.
I find this a bit difficult to believe. This would only apply if the threads on the regulator and the cylinder were tapered. Because a tapered thread connection stops going in once the male and female diameters are the same, using tapered threaded parts would require highly precise machining so that the male would stop going in at the precise distance to firmly seat the ball in the socket. Such precision would be prohibitively expensive. (I think.)
Rather I think the reason is because white Teflon tape is not 100% Teflon and the other component is combustible. There is a green Teflon tape for use with oxidizers that is 100% Teflon. To avoid the use of the more common tape on an oxygen cylinder, the easiest way is to say "No Teflon tape on gas cylinders."
When appropriately used, the Teflon tape acts as a lubricant, so that a regulator can be put on (and taken off) without the use of an enormous wrench.
I know that I may be entirely wrong about this, so I am seeking the expert opinion of L-CHASers.
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